The present invention relates generally to the field of computer system resource management, and in particular to a method and apparatus for tracking program execution time.
In an effort to capitalize on the rapidly-expanding market for on-line computer services, local cable television operators have begun investigating ways of providing on-line computer services to subscribers over existing cable networks. An attractive selling feature for such services is dramatically-improved access speed enabled by hybrid fiber coax cable networks, as compared to the often frustratingly-slow access speeds available with the more common POTS (Plain Old Telephone System) access methods.
A key challenge faced by cable operators, both from a technical and a business standpoint, is how to bill subscribers for the on-line services they receive. One possible approach is to use the same method currently employed by most cable operators for television services; namely, a flat monthly rate for unlimited usage. This approach is rather inflexible, however, tending to punish low-volume users while conferring a windfall of sorts on high-volume users. Moreover, while subscribers for television services are accustomed to such flat-fee billing practices, many current users of on-line services are accustomed to billing practices more closely tailored to their actual usage. Most on-line service providers can bill customers at an hourly rate based on actual usage. It is therefore desirable for cable operators to be able to offer this same type of flexible billing.
Another challenge faced not only by cable operators, but more generally by any entity providing on-line services, is how to tailor information or services to the particular desires of individual clients. One way in which this is done is by maintaining individualized "profiles" for subscribers. A user profile can be a highly-effective marketing tool, enabling a service provider to offer specialized services or content to subscribers based on their individual interests and preferences. Such profiles have commonly been created with the aid of a user survey. A less intrusive, and therefore more desirable, method of compiling a user profile would be to gather information about the applications actually used by a subscriber.
One way in which a cable operator may provide on-line services to subscribers involves an arrangement in which the cable operator maintains a central server computer accessible by large numbers of subscriber (client) computers over standard cable connections. The cable operator's server may itself provide on-line services to subscribers, such as Internet access, or it may function as a proxy through which subscribers can access other on-line service providers (OSPs), such as AmericaOnline.TM. and Prodigy.TM.. Combinations of these methods are also possible.
To facilitate a client-server arrangement of this type, a cable operator may furnish software for installation on a client computer providing an interface for accessing on-line services from or through the cable operator's server. Such client software would typically permit a subscriber to browse and launch cable-specific applications (that is, applications provided directly or indirectly by the cable operator's server). As noted above, it may be desirable for both billing and marketing purposes for the client software to track the subscriber's usage of cable-specific applications and periodically report such information back to the server. Unfortunately, tracking application program usage is not necessarily a straight-forward process, particularly in a Windows.TM. 3.n/95 or similar multitasking operating environment.
Multitasking (the ability to concurrently run multiple applications) is a characteristic feature of any Windows.TM. or Windows.TM.-like operating system. Such operating systems generally maintain a system task list identifying all currently-running applications. Relatively little information is kept in the system task list, however, usually being limited to a handle for locating the application and perhaps a title. System task lists of this type notably fail to provide detailed information concerning relationships between or among active applications. For example, a so-called "parent" application may spawn several "child" tasks, all of which would appear separately in the system task list. Moreover, a parent application may spawn a child task and then immediately terminate, in which case only the child task appears in the system task list, likely with attributes that are entirely different from those of the parent task.
Tracking the relationships between parent and child tasks can be highly useful, especially in the context of the above-described client-server application. For example, a cable operator may choose to bill a subscriber only in terms of a parent application, but have the usage total for the parent application reflect any usage of applications spawned by that parent application. Unfortunately, due to the various permutations in the way programs may be implemented in a multitasking environment, as well as the limited information about task relationships typically available from such systems, it becomes a difficult and complicated undertaking to accurately track program usage with currently-available technology.